HP40Nb

Use & Application

These consumables are designed to match heat resistant cast alloys with 0.4%C-25%Cr-35%Ni-Nb, including those micro-alloyed with Ti to increase creep resistance. They are also suitable for the Nb free alloys and leaner high carbon Cr-Ni alloys such as HK40, HT40 and IN519 where overmatching weld metal will normally be acceptable. Alloy HP40Nb is not prone to sigma phase embrittlement and the presence of eutectic and secondary carbides provide excellent hot strength and creep resistance in the typical service temperature range 900-1100°C. High levels of Cr and Ni provide good resistance to oxidation and carburization. The principal applications are **pyrolysis coils and reformer tubes for ethylene production in the petrochemical industry**. Generally preheat is not required.

Alloy type

Consumables to match 0.4%C-25%Cr-35%Ni-Nb heat resistant cast alloys.

Microstructure

In the as-welded condition the weld metal consists of austenite with eutectic and secondary carbide.

Materials to be welded

Also suitable for high carbon 18%Cr-37%Ni-Nb alloys e.g.W.-Nr 1.4849.
EN W.Nr.: 1.4857 (G-X40NiCrSi 35 25), 1.4853 (X 40 NiCrNb 35-25).
ASTM: A297 HP40Cb, A297 HP, A297 HP40.
PROPRIETARY: Paralloy H39W (Doncasters Paralloy), Lloyds T64 (LBA), MO-RE® 10, 10-MA (Duraloy), Thermalloy 64 (Duraloy), Manaurite® 36X, 36XM (Manoir Industries), Pyrotherm G25/35Nb, NbTZ (Pose Marre), Centralloy® 4852, 4852 Micro (Schmidt + Clemens), E2535Nb, E2535Nb-MA (Engemasa), Paralloy H39 (Doncasters Paralloy), Lloyds T63 (LBA), HR33 (Cronite).